Syed Farook and Tashfeen Malik, a California couple of Pakistani descent, gunned down 14 people at an office party on Wednesday morning before being killed shortly after in a gunfight with police.

A police officer stands guard inside an area roped off with crime scene tape near a home being investigated by police.(AP)

Syed Farook and Tashfeen Malik, a California couple of Pakistani descent, gunned down 14 people at an office party on Wednesday morning before being killed shortly after in a gunfight with police.

Authorities were still searching for a motive though plenty of signs pointed to the elaborate planning behind the shooting. Terrorism was not being ruled out.

“It’s possible that this was terrorist related, but we don’t know,” President Barack Obama said on Thursday. “And it’s also possible that this was workplace related.”

“We have not ruled out terrorism,” area police chief Jarrod Burguan said on Wednesday. “Based on what we have seen and how they were equipped, there had to be some kind of planning that went into this.”

Initial reports had suggested three shooters, and police have arrested a man but they have said they are investigating if that person is connected to the shooting.

Farook, 28-year-old public health official of the local county, had apparently stormed out of an office party to celebrate the holiday season at a health facility in San Bernardino.

He returned shortly with his wife, Malik, 27. Both were wearing protective gear and carrying assault rifles, authorities said.

They had left their six-month-old daughter with Farook’s mother in the morning, a sure sign, law enforcement officials are saying, that indicated they had planned the shooting.

“I have no idea why would he do that,” Farook’s brother-in-law, Farhan Khan, said at a news conference. “I have absolutely no idea. I am in shock myself.” They last spoke a week ago.

The shooting took place at Inland Regional Center, a health facility that deals with those with developmental disabilities. It employs nearly 670 employees and cares for 30,200 people.

Farhan Khan (C), brother-in-law of San Bernardino shooting suspect Syed Farook, speaks at the Council on American-Islamic Relations during a news conference in Anaheim.
(REUTERS)

Farook and Malik fled the scene of the shooting in a black SUV. But they didn’t get very far. They were killed in a gun battle with police on a street just 3.2 km away.

Some reports said Farook had travelled to Saudi Arabia a year ago, but authorities had yet to ascertain if it is linked to the shooting. Others reported he had changed in the last six months.

The Council on American-Islamic Relations (CAIR) said Farook’s family was from South Asia — others said Pakistan — and Malik came with her family from Pakistan.

Farook was born in Chicago. His father, also called Syed Farook, told some news outlets his son was a devout Muslim.

Malik held a Pakistani passport and was in the US on K-1 (fiancee) visa, said the FBI, which is now leading the investigation into the California shooting.

She arrived in the US in July 2014 with Farook, the FBI said. The two had visited Pakistan is the past.

CAIR’s Hussam Ayloush urged people not to jump to conclusions. “Is it work?” he said. “Rage-related? Is it mental illness? Extreme ideology?”

Shortly after the shooting, Obama spoke of it as another case of mass shooting. In a pre-scheduled interview to CBS, he said: “We have a pattern now of mass shootings in this country that has no parallel anywhere else in the world. There are steps we can take…to improve the odds that they don’t happen as frequently.”

This shooting came just two days after a lone gunman killed three people, including a police officer, at a women’s health center in Colorado Springs, Colorado. Obama had reacted with growing frustration, saying it’s time to say “enough is enough” and do something about easy access to guns in the US.

Democratic presidential frontrunner Hillary Clinton said, “I refuse to accept this as normal. We must take action to stop gun violence now.”

Republican frontrunner Donald Trump said, “California shooting looks very bad. Good luck to law enforcement and God bless. This is when our police are so appreciated!”